He spent six seasons with Dundalk, winning the League with the team in 1994/95 (scoring 2 goals in 26 appearances).
During this tenure at Dundalk he won the PFAI "Young Player of the Year" award in 1992/93 PFAI.
Purdy later moved to Derry City for one season where he won another league title for the 1996/97 season.
He joined Shamrock Rovers in the summer of 1997 where he stayed for four seasons, making two appearances in Europe (scoring once).Purdy was capped by Ireland at U15, U16, U17, U18 and U21 levels.
He played in two qualifiers in the 1990 UEFA European Under-18 Football Championship qualifying campaign.
His eldest son, Daniel, is currently playing for Longford Town and has played for Ireland U15s and U17s.
His other son Richie plays for Shamrock Rovers U19 in the League of Ireland U19 Division.